Plaster wall with divider strips with exposed coated concave surfaces



3,383,818 IPS WITH EXPOSED May. 2 1, 1968 R. E. TATUM PLASTER WALL WITH DIVIDER S'IR COATED CONCAVE SURFA Filed Oct. 12, 196

FIGI

inv smog ROY E. TATUM ATTORNEYS United States Patent 3 383,818 PLASTER WALL WITH DIVIDER STRIPS WITH EXPOSED COATED CONCAVE SURFACES Roy E. Tatum, Detroit, Mich., assignor to Blakely Products Company, Warren, Mich., a corporation of Michigan Filed Oct. 12, 1965, Ser. No. 495,260 1 Claim. (Cl. 52-371) ABSTRACT OF THE DISCLOSURE A rigid divider strip for use as a joint between adjacent sections of a wet plaster-like wall surface comprises a generally T-shaped cross-section with the vertical leg of the T projecting outwardly away from the base wall and being exposed. The outer end is concave and decoratively painted, and serves as a guide for establishing uniform plaster thickness.

This invention relates generally to divider strips for plaster type walls, and more particularly, to strips for dividing such wall surfaces into a plurality of sections.

In the application of relatively thick coatings of plaster or plaster-like materials to wall surfaces, it is desirable to divide the wall into a plurality of panels so as to control or prevent the creation of cracks in the plaster re sulting from external loading or thermal stresses. This method of construction is similar to that employed in the pavement arts, where expansion joints are spaced at intervals in sidewalks and roadways.

Thus, it is an object of this invention to provide a divider strip which functions to control or reduce cracking of the plaster-type wall and which also functions as a means to control uniform coating of plaster upon the base wall and, in addition, is decorative in appearance to enhance the overall appearance of the finished wall.

Other objects and advantages of this invention will become apparent upon reading the following specification of which the attached drawings form a part.

In these drawings:

FIG. 1 is a cross-sectional, plan view of a completed wall including the divider strip herein and a plaster-like coating.

FIG. 2 is a perspective view of a portion of a divider strip and wall.

FIG. 3 is a front view of a portion of the divider strip.

FIG. 4 is an end view of the strip.

Referring now to the drawings, FIG. 1 illustrates a portion of completed wall incorporating two divider strips 10. The wall comprises a rough or base wall 12, which may be made of rough plaster, masonry, or the like, and a finished wall surface 14 which is applied to rough wall 12.

The finished wall surface may be approximately A3 to 4 inch in thickness and may be formed of conventional finishing plaster, or one of the many available plasterlike finishing materials, such as a mixture of small chips or pieces of stone and a suitable binder.

The divider strips (see FIGS. 2 and 3) are long and of uniform cross-section. They include a base portion 16, which is flat on one side and tapered on the other, and a centrally disposed flange 18. The flange 18 is relatively broad at its outer end compared with its 3,383,818 Patented May 21, 1968 ice width at the intersection with base 16, and its outer face 20 is concave with two outer guide edges 22.

While dimensions may be varied, one suitable size is a strip whose base is about one inch wide, with the depth of the flange thus being about /3 inch.

Each divider strip is secured to the base wall 12 by means of nails or screws or the like which are inserted through mounting slots 24 formed in the strip.

In use, divider strips 10 are arranged at appropriate intervals and secured to the base wall 12. The plasterer then applies the finished wall coating 14 to base wall 12. In order to obtain a uniform thickness of wall surface 14 and a smooth surface, the plasterer then places his plastering darby so that it bridges horizontally across at least two of the divider strips 10. By then sliding the darby in a vertical direction along the two vertical divider strips 10 a smooth surface and uniform thickness can be achieved.

It will be noted that flange 18 is broader at its outer end than it is at the point of intersection with base 16. This establishes an undercut which serves to interlock the finished wall surface 14 with the divider strip 10, and to thereby firmly secure the edges of the finished wall surfaces 14 to base wall 12.

For decorative purposes paint may be applied to the concave outer edge 20 of flange 18 prior to plastering. This concavity serves to protect the paint from being scraped away or damaged during plastering.

This concavity also greatly facilitates the cleaning of the strip. After the finished wall 14 has been applied and while it is still unhardened, the plasterer can run a rag or his finger down the concave surface 20 and thereby remove any wet plaster which may have spilled over onto that surface. This cleaning of the strip can be much more readily and accurately accomplished in the case of the concave surface than could be done with a surface flush with the outer face of the finished plaster 14, since edges 22 serve to guide the finger or rag during this Wiping operation. Cleaning of the full width of the paint channel with a single pass can be achieved, yet there is no danger that the plaster surface might be unintentionally smeared. This invention may be further developed within the scope of the following claim. Accordingly, the above description is to be understood as illustrative of only a single embodiment and is not to be interpreted as strictly limited to this embodiment.

I now claim: 1. In a wall construction comprising a monoplanar base wall; a divider and guide strip forwardly thereof; and two coplanar wet plaster wall segments also forwardly thereof and separated by and edged to said strip and having their forward faces levelled to the front face of said strip; with the strip having a T section and whereof the cross bar portion is monoplanar and rests against the base wall and is secured thereto; and the leg portion projects forwardly from the base wall to separate the wet plaster segments so that these may have their exposed faces levelled against the front face of the leg portion;

the improvement which comprises such front face being concaved and precoated throughout its length;

with the concavity of the front face of the strip insuring the precoating being behind the front surfaces of the Wet plaster segments so as to be cleared by a levelling tool which bridges the segments;

J G and with the concavity also guiding a wiping finger tip moved along the front face of the strip for cleaning it in a manner to insure such finger tip from moving to and marring the front faces of the wet plaster segments.

References Cited UNITED STATES PATENTS 2,272,762 2/1942 Awbrey 52371 X 3,015,194 1/1962 Clark 52371 X 1,989,814 2/1935 MacNab ct a1 52-468 5/1955 Penton 52396 4/1957 Primus 523 67 X 6/1957 Wollagger 52255 X 3/ 1960 Grunwald 52717 FOREIGN PATENTS 3/1962 France. 4/1957 Great Britain.

HENRY C. SUTHERLAND, Primary Examiner. ALFRED C. PERHAM, Examiner. 

